They rightly do inherit heaven's graces, (5)
Unlike the lines we've seen so far, the admiration here is pretty obvious. First of all, he sticks in the word "rightly," which shows that he approves of how the powerful people turn about. But, more than that, he's saying that they "inherit heaven's graces" for crying out loud. That's some pretty strong praise, if you ask us. But again, it's possible he's only talking about powerful people who also show restraint. It's not like any powerful person gets a one way ticket to heaven.
And husband nature's riches from expense; (6)
Pretty much the same goes for this line as goes for line 5. Even if line 6 is a bit less extreme than the one that comes before it, it's still pretty intense to say that these powerful people are actually in charge of making sure that "nature's riches" don't get wasted. That definitely counts as admiration in our books.
They are the lords and owners of their faces,Others but stewards of their excellence. (7-8)
These lines are also pretty unambiguous in their admiration. Here, Shakespeare uses a class metaphor to suggest that the powerful people are at the top of the social hierarchy, while everybody else is merely a servant.